Comment by _yosefk | Hacker News Reader

Comment by _yosefk | Hacker News Reader

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"Far as I knew, it dominated desktop due to backward compatibility and other strategies. It wasn't open in many ways." - we're agreeing here, I said "it was less open than competitors at the time, which was perhaps one reason for its success." The only part we're disagreeing about is, I think it's more open than newer products (as a part of the general trend of hardware getting more closed.)

I worked on chips which included both ARM and MIPS CPUs; I don't think it makes ARM or MIPS "open" in many of the ways that matter, because, for one, programming those chips without the consent of the company that made them is very problematic both technically and legally. So ARM and MIPS in practice are "open" to select partners who make chips which are in turn "open" to select partners, unlike the PC where you have not only Windows, Linux, BSD etc. but things like MenuetOS and TempleOS and it's both legal and technically feasible to do this kind of thing. Of course this isn't due to Intel or anyone else behind the PC being more benevolent than other vendors, it's just an older platform and closeness wasn't or at least didn't seem as important for profitability as it is today. Here BTW Intel's focus on backward compatibility is very helpful - low-level software for the ARM or MIPS becomes obsolete more quickly and developing working low-level software for newer version of these in a timely manner might require partnering with the vendor, AFAIK. Basically ARM and MIPS are way more open than x86 to me as a chip architect (although an ARM architecture license AFAIK costs $30M or so... meaning that a lot of chip makers ought to take whichever implementation ARM provides and you're at their mercy to a much greater extent than you'd often desire), but they are far from fully open and then they're way less open than x86 to the users.

And then both MIPS and ARM are pretty old... the trend of really closing everything, where you can't get any spec without partnering with the vendor, didn't take off until maybe the 2000s.

I wonder what it'd take for open IPs to gain significant traction in hardware. It's easy to come up with reasons for them to fail or succeed but it's not easy to predict which reasons will end up more dominant.

"I worked on chips which included both ARM and MIPS CPUs"

That's really neat. Especially as I work a little on methods for secure HW/SW design. Mostly done with digital side of ASIC methodology but still custom digital and analog stuff to figure out. Appreciate any tips you have on such threads where I'm exploring.

"So ARM and MIPS in practice are "open" to select partners who make chips which are in turn "open" to select partners, unlike the PC where you have not only Windows, Linux, BSD etc. but things like MenuetOS and TempleOS and it's both legal and technically feasible to do this kind of thing. "

So, back then, ARM and MIPS I.P. holders didn't allow a PC-like product to be built with their chips? It was custom negotiated for every product with no platforms available? I could see you calling that less open and the ecosystem hit it would have.

"I wonder what it'd take for open IPs to gain significant traction in hardware. It's easy to come up with reasons for them to fail or succeed but it's not easy to predict which reasons will end up more dominant."

Inherently safer or language-specific ISA's like jop-design.com or crash-safe.org. Microcontrollers where any royalties are eliminated to further lower costs. OEM's targetting hobbyists and/or idealists that want maximum freedom. Anti-subversion efforts where multinational pride kicks in with an ISA like RISC-V being remixed allows everyone to feel like the owner. Tools or projects for processor design in academia where they just want something to work with and build rather than screwing around with I.P. and legal risk. Wait, that last one already happened and I already named it. ;)

So, given you've done hardware, what do you think of my recommendation that market wanting OSS hardware just build on Gaisler's SPARC products? There's a configurable CPU (Leon3) and substantial I.P. library already GPL'd or licensable. Probably closer to MIPS than ARM in price. There's also a 4-core version. One could put them right in an ASIC with Pi- or Novena-style boards w/ SPARC ecosystem (esp BSD/Linux) leveraged immediately. Alternatively, really my touch, is swapping out SPARC-specific stuff (eg instruction handling) for RISC-V so all the I.P. just magically supports a RISC-V solution. Open I.P. can gradually be developed to replace it, maybe keep using Gaisler's proprietary source where compelling, stuff is 90+% ASIC-proven from start, people can inspect, paid get paid, everyone is happy.

Nowadays there is ARM SBSA which aims to resolve the problems and allow a PC-like product to be built (the main reason such a thing didn't exist before is lack of interest). In the meantime the GPL helps to ensure at least the source code for the drivers for the Linux kernel are revealed.

BTW, notice the "server" in the ARM SBSA name.

Regarding the PC ecosystem vs the ARM and MIPS ecosystem - I'm not sure what happened back when MIPS and ARM made chips, just that most of their volume came when they were IPs, and at that point chip makers were keeping things rather closed. I'm pretty sure both Intel and say MS do not see the PC as the ideal model for their business, they just happen to profit more from it than they would from an attempt to kill it.

Generally, today ARM will sometimes break OS-level code between releases - something Intel would never do - and I think ARM does this because it sells an IP, not chips, and so in any case the only way to sell a CPU to a consumer is through a chip maker licensing ARM and then porting OSes to the new chip - and the chip maker can handle ARM-related breakage while they're at it. But it does not follow that ARM is to blame for most chips being closed and/or hard for an OS unsupported by the chip maker to work on the chip across its various generations; I'd guess that most of the difficulty comes from the chip-level breakage and lack of documentation, not CPU-level issues of this sort.

So IMO it's not that ARM or MIPS actively prevent(ed) the emergence of an open platform like the PC while Intel was pushing for open platforms; it's that Intel happens to have succeeded mainly selling chips for an open platform, while ARM and MIPS happen to have succeeded mainly selling CPU IP for various closed platforms.

Regarding the SPARC IP that you mentioned - I'd have to look at it more deeply to have an informed opinion. Generally for a chip vendor who wants source code, as opposed to wanting an open source IP, MIPS is just fine, they'll give you the source. Otherwise what you want from your CPU vendor varies (ARM for instance gives you not just the CPU but everything you need to build say a cellphone application processor - probably not the best one on the market, but a completely functional one. At the level of the CPU itself, you might want a bunch of things - like hardware virtualization support, or cache coherence with other processors, etc. etc. - that different vendors support differently, if at all.) So as I said, I don't think I have a serious opinion about the product you mention.

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